You have a great idea but you need more cash than you have in your account. You don't have a proven track record and potential investors are not giving you a chance. Your options are limited to friends, family and a small local network. You need to sell your idea, but you don't want to over-sell your friends and family.
One of the most common failures I see in startups is lack of focus. Unfocused entrepreneurs boast that their new technology will generate multiple disruptive products for consumers as well as enterprises around the world. Investors hear this as trying to do too many things with limited resources, meaning the startup will not shine at anything, and will not survive the competition.